'Oil' smudges on interior of lens: Have had the camera for 2 years. Dropped a couple times with no problems. However recently pictures have been displaying smudges - like oil on lens. I have cleaned exterior of lens with no change - so it appears to be coming from inside camera. Strange thing is - when shooting I can not see the smudges, but once I have taken photo I can see in camera display & when downloaded. So maybe not a lens issue. Bummer...